Robot
Across your work
Robot can read any of your compositions by name without opening it, from the copy you last saved or the newer one on this device, and look at your artworks and fonts. So it can reference one piece while writing another: "use the motifs from Canopy Flight".
For a question over a whole document or several ("which glyphs dip below the descender", "which layers use colours off the palette", "where does the bass cross the tenor"), Robot writes a short script and reads only its answer, which costs far less than reading item by item. Scripts only read: they can't change anything, and they run cut off from the network and the rest of the app. Ask Robot to keep one and it's saved in your files under files/scripts, to run again by name.
A script Robot runs shows in the chat as it goes: what it reads, how far it has got, its result and its code. Stop asks it to finish with what it has found so far; pressing Stop now ends it at once. Open shows the run in the Script window, where Edit lets you change the script and run it yourself.
You can write and run scripts without Robot too: search ⌘K for Write a read-only script. Saved scripts appear there as Run script: and their name, and in the Script window's list, so an audit runs again without a chat.
From Recents, ask for a new piece built on another one: Robot reads the reference, makes a new composition, opens it and writes it there. Ask for the same mood and the new piece takes the reference's colour themes too.
Robot can also change a document you don't have open, without taking you to it. Its changes wait as an unsaved draft on this device, and the card after its reply offers Keep (saves it), Discard (puts it back to how it was before that request), Preview (a picture of it now, in Robot's window, that follows as Robot keeps working) and Open. Discard works until the document changes again, for Robot's last 40 changes on this device and up to two weeks; after that, open it and undo there. A document open in another tab is left alone.